How do you calculate quoteable good-parts capacity for a job shop?

Multiply good parts per slot by available slots to get gross capacity, then multiply by availability and first-pass yield. Here 18 parts × 24 slots = 432 gross, derated by 82% availability and 96% yield, gives about 340 good parts.

Why is quoteable capacity lower than gross capacity?

Because machines are not available every booked hour and not every part passes first time. In this example 432 gross parts lose about 78 to unavailable shop time and another 14 to scrap and rework, leaving roughly 340.

What is a good shop availability percentage to quote at?

Most well-run shops sit between 75% and 90% practical availability once changeovers, maintenance, and breaks are counted. The 82% default is realistic; quoting at 95%+ usually overpromises and risks blown dates.

How does first-pass yield affect a job shop quote?

First-pass yield directly scales your deliverable count. At 96% yield, about 14 of 432 parts are lost to scrap and rework here; drop yield to 90% and you would lose roughly 43 parts, materially changing the promise.

Should I quote gross or net capacity to a customer?

Always quote net good-parts capacity. Promising the 432 gross figure ignores the 92 parts lost to downtime and scrap, so you would be committing to roughly 340 parts you can actually ship as 432.

How do I increase quoteable capacity without buying machines?

Raise availability by cutting changeover and downtime, or raise first-pass yield by tightening setup and inspection. Improving availability from 82% to 90% on this job would add over 30 deliverable parts with no new equipment.

Contract Manufacturing, Job Shop Quoting & Make-to-Order calculator

Job Shop Quote Calculator

This job shop quote calculator tells you how many good parts you can honestly promise in a quote window, after availability and yield take their cut. Estimators and production planners in make-to-order shops use it to avoid the classic trap of quoting gross capacity and then missing the date because machines were down or scrap ate the run. It starts from parts per slot and available slots, then derates for practical shop availability and quoted first-pass yield. The result is a defensible delivery number — what you can actually ship, not what the spec sheet implies.

What this calculator does

Estimate quoteable job-shop capacity for a custom part RFQ or make-to-order lot.
checking whether a requested lot size fits the open shop calendar before sending a quote
It computes quoteable good-parts capacity by derating gross slot capacity for practical shop availability and quoted first-pass yield.

Formula used

Gross quoted part capacity = good parts per production slot × available production slots in the quote window
Quoteable good parts capacity = gross quoted part capacity × practical shop availability × quoted first-pass yield

Inputs explained

good parts per production slot: Use the expected good-part output per machine slot, workcell slot, fixture load, or batch for the quoted routing.
available production slots in the quote window: Count only slots that can realistically be reserved before the requested due date after current backlog and planned downtime.
practical shop availability: Use realistic availability after setups, programming, changeovers, meetings, maintenance, and operator constraints.
quoted first-pass yield: Use yield from similar parts, materials, tolerances, inspection plans, and operators.

How to use the result

Use it during quoting and capacity planning to set a realistic deliverable quantity and lead time for a make-to-order job.
It assumes steady parts per slot and a single yield figure; mixed part complexity or learning-curve effects on a new job can shift the real number.

Current U.S. benchmarks

The U.S. prime lending rate is 6.75% (Federal Reserve via FRED, 2026-07-02). Payback and financing math should start from today's rate, not a remembered one.

Common questions

How do you calculate quoteable good-parts capacity for a job shop? Multiply good parts per slot by available slots to get gross capacity, then multiply by availability and first-pass yield. Here 18 parts × 24 slots = 432 gross, derated by 82% availability and 96% yield, gives about 340 good parts.
Why is quoteable capacity lower than gross capacity? Because machines are not available every booked hour and not every part passes first time. In this example 432 gross parts lose about 78 to unavailable shop time and another 14 to scrap and rework, leaving roughly 340.
What is a good shop availability percentage to quote at? Most well-run shops sit between 75% and 90% practical availability once changeovers, maintenance, and breaks are counted. The 82% default is realistic; quoting at 95%+ usually overpromises and risks blown dates.
How does first-pass yield affect a job shop quote? First-pass yield directly scales your deliverable count. At 96% yield, about 14 of 432 parts are lost to scrap and rework here; drop yield to 90% and you would lose roughly 43 parts, materially changing the promise.
Should I quote gross or net capacity to a customer? Always quote net good-parts capacity. Promising the 432 gross figure ignores the 92 parts lost to downtime and scrap, so you would be committing to roughly 340 parts you can actually ship as 432.

Last reviewed 2026-05-12.